Although biochar production technology is considered a more recent strategy for carbon sequence, the practice of adding charred bio mass a forestry waste to improve soil quality is not new. This process is modeled after a 2,000-year-old practice in the Amazonian basin, where indigenous people created areas of rich, fertile soil which is terra preta (meaning“dark earth”).
Biochar—a carbon-rich product used as a soil conditioner—is one of the more recent technologies in environmental governance. In the spirit of ecological modernization, biochar is claimed to offer many benefits for soil fertility and climate change mitigation. However, biochar has a long history. It was inspired by terra preta, a highly fertile soil of anthropogenic and pre-Columbian origin found in the Amazon.
Terra preta owes its distinctive black color to its weathered charcoal content and was created by mixing charcoal, bones, broken pottery, manure, and compost in low-fertility Amazonian soil.
What is the history of biochar?
History of Biochar as an Ancient Soil Amendment Biochar is a form of charcoal produced by superheating biomass. It is found naturally in soils around the world as a result of vegetation fires, and biochar has also been created and used by humans in traditional agricultural practices in the Amazon Basin of South America for over 2,500 years.
Low-Cost Biochar Production
Biochar is a by-product of biomass pyrolysis.in an oxygen-deficient environment. Application of Biochar production has paid significant attention to the ability to increase soil fertility, carbon sequestration, Biochar production and stabilization of organic and inorganic pollutants. vital body Informed Biochar Application of Knowledge Plant growth and an increase in biomass and nutrients Uptake under drought and salt stress.
Biochar Production through low-cost, small-scale production using modified stoves or kilns, or through large-scale, production, cost-intensive which utilizes larger pyrolysis plants and higher amounts of feedstocks. One of the most common ways to make biochar for on-farm use is through pyrolysis using a top-lit updraft biochar machine to produce charcoal.
Pyrolysis Processes for Biochar Production
The pyrolysis (or deamination) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change in chemical composition. The word is composed of the Greek-derived elements pyro "fire," "heat," "fever," and lys "separation." Pyrolysis is commonly used in the treatment of organic materials.
What is the mechanism behind this?
Pyrolysis of organic compounds normally yields volatile chemicals and a solid carbon-containing residue, char. Carbonization is a type of extreme pyrolysis that primarily produces carbon as a byproduct. The technique is widely used in the chemical industry to produce ethylene, various types of carbon, and other compounds from petroleum, coal, and even wood, as well as to make coke from coal. Carbonization emphasizes the carbon enrichment element of pyrolysis rather than the "breakdown" aspect. The terms "carbonization" and "pyrolysis" are often interchanged.
Conditioning refers to the change in the chemical and physical characteristics of biomass at temperatures between 110 and 180 °C, when the biomass begins to soften, and chemically bound water evaporates. Pyrolysis a biochar production process typically involves heating a material above its decomposition temperature, breaking the chemical bonds in its molecules. The fragments usually become smaller molecules, but they may combine to produce residues with larger molecular masses, even as amorphous covalent solids. In many settings, some amount of oxygen, water, or other substances may be present, leading to combustion, hydrolysis, or other chemical processes in addition to proper pyrolysis. Sometimes those chemicals are added intentionally, such as in the burning of firewood, in the traditional manufacture of charcoal, and in the steam cracking of crude oil. In contrast, the starting material may be heated in a vacuum or in an inert atmosphere to avoid chemical side reactions (such as combustion or hydrolysis). Pyrolysis a biochar production process in vacuum also lowers the boiling point of the byproducts, thereby improving their recovery.
Biochar production influenced from Amazon Forest
Whether these soils were intentionally made or are simply a by-product and waste of farming and cooking practices is still unclear. The fertility of terra preta is significantly higher than the otherwise famously infertile soils of the Amazon forest. This explains why plants grown in terra preta(dark earth) soil grow faster, and are more nutrient-dense, than plants grown in neighboring soils. In fact, terra preta soils continue to hold carbon production still today.
Biochar Production during pyrolysis, a thermal decomposition of biomass(forestry waste) in an oxygen-limited environment.
The quality of feedstocks, or materials burned, have a direct impact on the quality of the final biochar production. Ideally, clean feedstocks with 10 to 20 percent moisture and high lignin content must be used. Some good examples are field residues and woody biomass (Woodin forestry). Using contaminated feedstocks, including feedstocks from railway embankments or contaminated land, can introduce toxins into the soil, drastically increase soil pH and inhibit plants from absorbing minerals. The most common contaminants in Biochar Production are heavy metal including cadmium, chromium, copper, lead, zinc, mercury, nickel and arsenic and Polycyclic Aromatic Hydrocarbons.
Post-processing to enhance the biochar properties
The effectiveness of biochar can be changed by post-processing biochar.
Techniques may include:
Treat with phosphoric acid to increase functional groups, reduce pH, and create slow-release phosphate fertilizer,
Treat the biomass with alkalis (such as potassium hydroxide) to increase the pH and increase the content of
To increase N content, inject organic or inorganic nitrogen compounds such as urine.
Mix with nutrient-rich organic matter, such as compost. The mixture may need to be heated, sterilized, and dried to eliminate the biohazard and facilitate handling.
Add minerals such as rock phosphate, gypsum, dolomite, iron oxide, and lime to overcome specific soil barriers.
Add chemicals such as urea and diammonium phosphate to make a compound fertilizer.
Granulate or pelletize to aid in handling and biochar application.
Add steam or oxygen. (Note that this is not forming activated carbon, which occurs in the reactor.)